The last two have the disadvantage of using Freeverb3 and not a convolution reverb while the G-town Organ include real church ambiance.

Q: Where to get the organs demoed above?A: You'll find them all on sites mentioned in the list of sample libraries. G-Town Organ is part of the G-Town Church Sampling Project, Orgue Eglise can be found at Worra's Place (called "Pipe Organ" I believe) and Orgue de Salon at Burnie's Site.

Fun fact: It's supposed that Bach composed the Toccata in D minor to test an organ. The first thing Bach is said to have done when testing an organ is to pull out all the stops and play in the fullest possible texture, in order to see if the organ had good bellows to provide plenty of wind to the instrument: not enough and the pitch would be unsteady and tone quality would be inferior.

There is now also a version that uses a york minster impulse response as the reverb. It's in the gentoo pro-audio overlay and can be installed at the same time as the normal one, or you can install it from source after grabbing it here. It is called aeolus-ym and definitely worth the time to install.